Erin is a city in Houston County, Tennessee, United States. The population was 1,490 at the 2000 census. It is the county seat of Houston County.
Erin is located at 36°19′1″N 87°41′53″W / 36.31694°N 87.69806°W / 36.31694; -87.69806 (36.316998, -87.697946). The elevation is 480 feet above sea level.
According to the United States Census Bureau, the city has a total area of 4.1 square miles (10.6 km²), all of it land.